Drilling apparatus



Feb. 1, 1966 A. FISCHER DRILLING APPARATUS 3 Sheets-Sheet 1 Filed April9, 1963 INVENTOR.

ARTUR FISCHER BY MICHAEL S. S'TR/KER ATTOR 3 Sheets-Sheet 2 Filed April9,

Fig.9

Fig.70

INVENTOR.

ARTUR FISCHER BY MICHAEL S SYRIKER IQTTORNEY Feb. I, 1966 A. FISCHER3,232,364

DRILLING APPARATUS Filed April 9, 1963 3 Sheets-Sheet 5 IIIJI/ INVENTOR.

ARI'UR FISCHER BY lVl/CHAEL S. STRIKER #TTORNE) Patented Feb. 1, 1966 8Claims. (Cl. 175-403 The present invention relates to drilling apparatusin general and, more particularly, to an improved drilling apparatuswhich is especially suited for making expansion-anchor holes in masonry,such as concrete, brick, stone, rock, plaster, mortar and similarbuilding materials of brittle consistency. Such holes are often drilledto accommodate slotted parts of anchoring bolts which are thereuponcaused to expand and to engage with great force the material of a wallconstruction or the like. The tools of drilling apparatus which are usedfor making holes in granite, concrete or the like must be mounted insuch a way that they are held against rotation and against axialmovements with respect to their supports. Furthermore, since the toolsare subjected to considerable wear and tear, they must be mounted in amanner to permit rapid exchange without, however, aifecting the strengthof the connection between the tool and its support when the apparatus isin actual use.

Accordingly, it is an important object of the present invention toprovide a very simple but highly reliable connection between a drillingtool and its support and to construct such parts in a way to permitexceptionally simple and very rapid removal or reinsertion of the tool.

Another object of the invention is to provide a supporting member fordrilling tools which is provided with novel means for normallypreventing withdrawal of a tool and which may be coupled with the driveof a power drill or with a hand-operated drilling apparatus to transmitrotary motion to the tool. A further object of the invention is toprovide a drilling apparatus for making holes in concrete or the likewhich may be manufactured at low cost and which may be coupled withsolid rod-like tools or with specially configurated tubular drillingtools.

An additional object of the invention is to provide a novel connectionbetween a drilling tool and its supporting member which is constructedand assembled in such a way that the tool is automatically locked to thesupporting member when the drilling apparatus is in actual use.

A concomitant object of the invention is to provide a connection whichforms an integral part of the tool and/ or of the supporting member.

With the above objects in view, one feature of the invention resides inthe provision of a drilling apparatus, particularly for makingexpansion-anchor holes in granite, concrete, brick, plaster and thelike. This apparatus comprises a rotary supporting member which mayassume the form of an attachment adapted to be inserted into the chuckof a power drill and which comprises an end portion provided with aninwardly extending axial opening or bore, an elongated cutting toolhaving a toothed or conical cutting element at one end and a motiontransmitting portion at the other end thereof, and means including aslot or groove provided in one of these portions and a projectionprovided on the other portion and slidably extending into the slot fordrivingly coupling the supporting member with the tool. The projectionand the slot may constitute a bayonet lock or, alternatively, thedrilling apparatus may comprise special retaining means carried by thesupporting member and engaging with the tool for normally preventingwithdrawal of the motion transmitting portion from the opening in theend portion of the supporting member.

The tool may assume the form of a tubular body formed with a projectionwhich extends tangentially from the motion transmitting portion or,alternatively, the tool may be a solid profiled rod with a substantiallyradial projection which is obtained by deforming the motion transmittingportion so that the cross section of that part of the motiontransmitting portion which is adjacent to the projection is of smallerarea than the cross section of the remainder of the tool.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved drilling apparatus itself, however, both as to its constructionand the method of assembling its parts, together with additionalfeatures and advantages thereof, will be best understood from thefollowing detailed description of certain specific embodiments withreference to the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of a portion of a drillingapparatus which embodies one form of my invention;

FIG. 2 is a fragmentary partly elevational and partly sectional view ofthe parts which are shown in FIG. 1 and which are illustrated in partlyassembled position;

FIG. 3 is a transverse section as seen in the direction of arrows fromthe line III-III of FIG. 2;

FIG. 4 is a fragmentary partly elevational and partly sectional view ofthe parts shown in FIG. 2 which are illustrated in fully assembledposition;

FIG. 5 is a fragmentary partly elevational and partly sectional view ofa modified drilling apparatus whose parts are shown in fully assembledposition;

FIG. 6 is a transverse section as seen in the direction of arrows fromthe line VI-VI of FIG. 5;

FIG. 6a is a transverse section through a drilling apparatus which isvery similar to the apparatus of FIGS. 5 and 6 but whose tool isretained in its supporting member in a slightly different way;

FIG. 7 is a fragmentary partly elevational and partly sectional view ofan additional drilling apparatus wherein the tool is detachably securedto its supporting member by means of a threaded member;

FIG. 8 is a transverse section as seen in the direction of arrows fromthe line VIII-VIII of FIG. 7;

FIG. 9 is a side elevational view of a tool which may be used in certainof the drilling apparatus shown in FIGS. 1 to 8;

FIG. 10 is a transverse section as seen in the direction of arrows fromthe line X-X of FIG. 9, further showing a portion of a supporting memberwhich may be used to receive and to rotate the tool of FIG. 9;

FIG. 11 is a fragmentary exploded view of a drilling apparatus whereinthe supporting member and the drilling tool may be coupled by means of abayonet lock which includes an L-shaped groove or slot provided in theperiphery of the tool and a cooperating projection provided on thesupporting member;

FIG. 12 is an end view of the supporting member as seen in the directionof arrows from the line XIIXII of FIG. 11;

FIG. 13 illustrates the parts of FIG. 11 in partly assembled position;

FIG. 14 is a transverse section as seen in the direction of arrows fromthe line XIVXIV of FIG. 13;

FIG. 15 shows the structure of FIGS. 11 and 13 in fully assembledposition;

FIG. 16 illustrates the structure of FIG. 15 in a different angularposition and in partial axial section taken along the line XVIXVI ofFIG. 15; and

FIG. 17 is a fragmentary exploded view of a different drilling apparatuswherein the drilling tool is provided with a projection receivable in anL-shaped groove of the supporting member.

Referring now in greater detail to the drawings, and first to FIGS. 1 to4, there is shown a portion of a drilling apparatus which isparticularly suited for making expansion-anchor holes in concrete,plaster, brick and similar brittle building materials. Such holes areused to receive certain parts of anchor bolts, and the parts received inthe holes are thereupon caused to expand so as to retain the bolts withgreat force even if the nature of the surrounding material is such thatit is normally incapable of providing a strong support for a threadedbolt or a similar device.

The drilling apparatus comprises a rotary supporting member 1 which isnormally of cylindrical shape and whose front end portion 11) is formedwith an axial opening or bore 3 which extends inwardly from its end face10 and which communicates with a laterally extending groove or slot 4.This slot may but need not extend all the way to the periphery of theend portion 1b and is substantially tangential to the bore 3, seeparticularly FIG. 3.

The end portion 1b carries a retaining device which assumes the form ofa cap having an annular flange 5a and an inwardly extending annularcollar 5b which is rigid with the flange 5a and which overlies and isadjacent to the end face 10. The collar 517 has a central opening 50which communicates with an outwardly extending tangential recess 7, andthis recess may be moved into registry with the front end of the slot 4in response to rotation of the cap 5 about the end portion 1b of thesupporting member. As shown in FIGS. 2 and 4, the end portion 112 isformed with a circumferential groove 1:: which receives an inwardlyextending annular bead 6 at the rear end of the flange 5a so that thecap 6 is free rotate about but is held against axial movements withrespect to the supporting member. If desired, the bead 6 may be fittedin its groove la with at least some friction so that the cap 5 is notlikely to rotate with respect to the supporting member unless it isgrasped by fingers or by a suitable tool.

The end portion 112 further comprises an internal shoulder 3a whichextends into the bore 3 at a given distance from the end face 1c andwhich serves as an abutment or stop for the motion transmitting portion2c at the rear end of a specially configurated drilling tool 2 bestshown in FIG. 1. The tool comprises at its front end a cutting element2a of toothed profile. The exact construction of this tool forms no partof my invention and the method of making it will be described solely forthe purpose of completing the disclosure. In making the tool, one startswith an L-shaped blank or plate of tool steel which is thereupon rolledor convoluted about an axis parallel with one of its legs so as to forma tubular body and that the other leg extends tangentially from thetubular body. This laterally or tangentially extending non-convolutedleg then forms a fiat projection or lug 2d which serves to hold the tool2 against rotation with respect to the supporting member 1 when themotion transmitting portion 20 of the tool is inserted into the bore 3.The projection 2d then fits into the slot 4 and cooperates with thewalls bounding this slot to prevent angular displacements of the portion2c with respect to the end portion 111. The rear end face 2c of themotion transmitting portion 2c abuts against the shoulder 3a and theaxial length of the projection 2d is normally selected in such a waythat its front end face is very near to or actually abuts against theinner side of the collar 5b when the end face 2e abuts against theshoulder 3a. This insures that the tool 2 is held against axialrovements with respect to the supporting member 1 (see FIG. 4)excepting, of course, at such times when an operator intentionally turnsthe cap 5 to a position in which the recess 7 registers with the slot 4(FIG. 2) so that the motion transmitting portion 20 may be withdrawnfrom the end portion 112.

The teeth of the cutting element 2:: are preferably formed before theblank is convoluted to assume the shape of a tubular body. As a rule,the blank may be stamped from a larger sheet of tool steel or similarwearresistant material. The slot 2b which is best shown in FIG. 1 lendssome elasticity to the tool and provides a path for the escape ofconcrete, brick, mortar or like material when the drilling apparatus isput to actual use. The projection 2d may form part of a comparativelylong arm which is shortened by cutting, filing or in any other suitableway after the blank is convoluted into a slotted body of tubular shape.

The rear end portion 10 of the supporting member preferably assumes theform of a wedge which may be inserted into the drill chuck of a powerdrill or into the chuck of a manually driven drilling or boringapparatus. Of course, the supporting member may be coupled directly tothe output shaft of an electric motor or to the output shaft or" atransmission which is driven by the motor of a drilling apparatus.

FIGS. 5 and 6 illustrate a portion of a slightly different drillingapparatus whose supporting member 11 is very similar to the supportingmember 1 excepting that its end portion 11b need not be provided with acircumferential groove because the projection 12d which forms part ofthe motion transmitting portion 120 of a tubular tool 12 is releasablyretained in the bore 13 in a slightly different way. This projection 12dagain fits into a laterally extending slot 14 which is substantiallytangential to the bore 13, and its front end face 12f (i.e., that endface which is turned toward the non-illustrated cutting element of thetool 12) is spaced inwardly from the end face of the portion 11b so thatit may be engaged by a pin 18 which is fitted into a transverselyextending eccentric bore 11) of the end portion 11b. In the embodimentof FIGS. 5 and 6, the pin 18 is nearly entirely concealed in the bore11] and is held merely by friction so that it cannot be ejected bycentrifugal force when the supporting member 11 is caused to rotate. Therear end face 12a of the motion transmitting portion 12 abuts against aninternal shoulder 13a of the end portion 11b so that the shoulder 13aand the pin 18 cooperate to hold the tool 12 against axial movementswith respect to the supporting member. Angular movements of the tool areprevented by the projection 12d which has a sliding fit in the slot 14and which may be withdrawn from this slot as soon as the pin 18 isremoved.

FIG. 6a illustrates a slightly different arrangement wherein theprojection 22d of a tubular tool 22 is formed with a bore 22g which isin registry with the transverse bore 21 of the end portion 21b. The pin18 is replaced by a threaded bolt 28 whose head 28a may be engaged byfingers and whose threaded terminal portion may be screwed into thethreaded portion of the bore 21]. An important advantage of thearrangement shown in FIG. 6a is that the cutting tool 22 may beexchanged with little loss in time and that no special tools arenecessary for such operation.

FIGS. 7 and 8 illustrate a supporting member 31 which is similar to thesupporting member 11 and which serves to transmit rotation to and tosupport a slightly different tubular tool 32 having comparatively shortprojection 32d which extends tangentially from the motion transmittingportion 320, the latter being slidably received in the axial bore 33 ofthe end portion 31b of the supporting member and abutting against ashoulder 33a. The retaining means for the motion transmitting portion320 comprises a comparatively short threaded member, such as aconventional screw 39 with aslotted head, and thisscrew is driven into aradial bore 31 of the end portion 31b so as to bear with its tipdirectly against the portion 320 of the tool. This portion 320 isresilient because the tool 32 is slotted so that the screw 39 willsafely hold the tool against any axial movements. As shown in FIG. 7,the projection 32d extends all the Way to the periphery of thesupporting member 31 to fill the respective section of the slot 34, andthe arrangement is preferably such that the end portion 31b is formedwith a depression which receives the head of the screw 39 so that thishead stands in the way of the projection 32d and prevents axialmovements of the tool even if the tip of the screw does not engage themotion transmitting portion 32:. Tthe head of the screw 39 thuscooperates with the internal shoulder 33a of the supporting member 31.

It will be readily understood that the screw 39 may be arranged in sucha way that its head engages only against the front end face of theprojection 32d or that its tip engages only the projection rather thanthe tubular portion 32c. For example, and referring to FIG. 8, the screwmay be substantially perpendicular to and may bear with its tip againstthe underside of the projection 32d so that the arrangement would thenresemble the one which is shown in FIG. 6a excepting that the screwwould not extend through the projection.

, It is to be mentioned here that the tubular tool 2, 12, 22 or 32 maybe held against rotation even if that portion which fits into therespective supporting member is without a projection. All that isnecessary is to provide a projection on the supporting member and toinsert the tool in such a way that the projection fits into thelongitudinal slot of the tool. Thus, and referring for example to FIG.7, the supporting member 31 may be provided with a radially inwardlyextending lateral lug which projects into the bore 33 and which may bereceived in the longitudinal slot of the tool 32 which latter is thenwithout the projection 32d. This modification is so obvious that it canbe readily comprehended without a separate illustration.

FIG. 9 illustrates a somewhat different drilling or cuting tool 42 whichassumes the form of a solid rod and which is. preferably profiled in amanner best shown in FIG. 10. The tool comprises a conical cuttingelement 42a at One end and a motion transmitting portion 42c at theother end thereof, and this motion transmitting portion 42c comprises asubstantially radially extending projection 42d which assumes the formof a flat lug and which may be fitted into a radial slot 44 provided inthe end portion 41b of a rotary supporting member 41 shown in FIG. 10.The end portion 41b has an axial bore 43 which receives the motiontransmitting portion 420. The projection 42d is formed by an upsettingor pinching machine as is evidenced by the small depressions 42/1 atboth sides of this projection, i.e., the cross section of that part ofthe motion transmitting portion 421: which extends along the projection4241 is smaller than the cross section of the remainder of the tool. Bymaking the projection 42d in the just described manner, one can producethe tool 42 by cutting a predetermined length from an elongated bar orrod of tool steel, by sharpening one end of the thus obtained blank toform the conical cutting element 42a, and by thereupon upsetting orpinching the motion transmitting portion 42c to form the projection 42d.

The tool 42 may be held in the supporting member 41 by a cap such as thecap of FIGS. 14 or in a manner as shown in FIGS. 5-6 or 7-8. This too]is provided with a series of axially parallel reinforcing ribs and isreleasably held in the supporting member by a pin 43. Drilling apparatuswith tools of the type shown in FIGS. 9 and 10 are used for making holesin granite or in other hard building materials which are likely todeform or to break a thin-walled tubular tool.

FIG. 11 illustrates a portion of a drilling apparatus wherein anelongated tubular drilling tool 52 is coupled to a supporting member(see also FIG. 12) by means of a bayonet lock including an L-shapedgroove or slot 54 provided in the periphery of the motion transmittingportion 520, and an internal projection 52d extetnding into the axialbore 53 of the end portion 51b. The motion transmitting portion 52c ofthe tool 52 is receivable in the bore 53 when the projection 52d is inregistry with the open end of the axially parallel section 54a of theslot 54. The other end of this section 54a communicates with a secondsection 54b which extends circumferentially of the motion transmittingportion 520 and which resembles a portion of a helix. When theprojection 52d slides in the section 54b in a direction away from thesec tion 54a (i.e., when the tool 52 is rotated in an anticlockwisedirection, as viewed in FIG. 13), the end face 52c of the motiontransmitting portion 52c comes into abutment with the bottom wall 53a ofthe bore 53 and cooperates with the projection to hold the tool againstaxial and angular movements (in one direction) with respect to thesupporting member or vice versa.

FIGS. 13 and 14 illustrate the tool 52 and the supporting member 51 inpartly assembled position. The projection 52d is located at the innerend of the section 54 and the tool is ready to be rotated in ananticlockwise direction, as viewed in FIG. 14, so that it will be wedgedin the end portion 51b as soon as the end face 52e comes into abutmentwith the bottom wall of the bore 53. Such position of the parts 51, 52is shown in FIGS. 15 and 16.

In order to detach the tool 52, the operator merely rotates thesupporting member 51 in a clockwise direction, as viewed in FIG. 15 or16, and thereupon withdraws the tool from the bore 53. It willbeunderstood that, when the drilling apparatus is in actual use, thesupporting member 51 is driven in a counterclockwise direction, asviewed in FIG. 15; otherwise, the projection 52d would return into thesection 54a as soon as the non-illustrated cutting element of the tool52 would abut against a solid body, such as a wall made of brick,concrete or the like. In other words, when the drilling apparatus is inactual use, the supporting member 51 must be rotated in a sense to movethe projection 52d toward the closed end of the helical slot section5411. The pitch of the section 54b is such that the projection 52d mayenter this section but that the end face 52e is compelled to engage thebottomwall 53a at the time when or before the projection reaches theclosed end of the section 54b.

, FIG. 17 illustrates a slightly modified drilling apparatus wherein theprojection 62d is provided on the periphery, of the motion transmittingportion 62c forming part of a tubular drilling tool 62. This projection62d formspart. of a bayonet lock and may be received in an L-shapedgroove or slot 64 which is provided in the internal surface of the endportion 61b forming part of a rotary supporting member 61. The slot 64has an axially parallel section 64a whose open outer end is located attheend face of the end portion 61b, and a helical section-64b whichcommunicates with the inner end of the section 64a and which is inclinedin such a way that the end face 622 of the motion transmitting portion620 is compelled to abut against the bottom wall 63a of the axial bore63 before or at the time the projection 62d reaches the closed end ofthe section 64b.

The tool 52 or 62 may be manufactured at low cost by stamping arectangular blank from a sheet of tool steel and by thereupon rollingthe blank into the form of a tube. The projection 62d may be welded ontoor otherwise secured to the motion transmitting portion 62c. In itspreferred form, the projection 52d or 62d assumes the shape of ahemispherical body. It goes without saying that the bayonet lock ofFIGS. 11-16 or FIG. 17 may be used in connection with solid rod-shapeddrilling tools of the type shown in FIGS. 9 and 10, and that it is notalways necessary to form the slot 54 or 64 with a helical section.

The main difference between the drilling apparatus of FIGS. 1 to 10 andthe drilling apparatus of FIGS. 11 to 17 is that the bayonet lock servesas a means for holding the drilling tool against axial and angularmovements with respect to the supporting member. On the other hand, thearrangement of FIGS. 1-10 is capable of holding the tool against angularmovements in a clockwise or anticlockwise direction. Thus, when the tooland its supporting member are coupled by means of a bayonet lock, caremust be taken to rotate the supporting member in a direction which willcause the projection 52d or 62d to move toward the closed end of thehelical slot section. Such precaution is not necessary when theconnection between the tool and its supporting member comprises aretaining means such as the cap 5 or the pin 18.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a drilling apparatus, particularly for making holes in concreteand the like, in combination, a rotary supporting member comprising anend portion provided with an inwardly extending axial bore and with aslot extending substantially tangentially from and communicating withsaid bore; an elongated cutting tool of tubular shape, said tool havingan annular cutting element at one end and an annular motion transmittingportion at the other end thereof, said motion transmitting portion beingslidably received in said bore and comprising a substantially tangentialflat lateral projection slidably received in said slot to hold said toolagainst rotation with respect to said supporting member; and retainingmeans detachably carried by said supporting member and releasablyengaging said motion transmitting portion for normally preventingwithdrawal of said tool from said end portion.

2. In a drilling apparatus, particularly for making holes in concreteand the like, in combination, a rotary supporting member comprising anend portion having an end face and provided with an axial bore extendinginwardly from said end face, said end portion further having a slotextending laterally from and communicating with said bore andterminating at said end face; an elongated substantially tubular cuttingtool having an integral annular cutting element at one end and a motiontransmitting portion at the other end thereof, said motion transmittingportion being, received in said bore and having a substantially fiatelongated projection which is parallel with the longitudinal extensionof said tool and is slidably received in said slot so as to hold thetool against rotation with respect to said supporting member; andretaining means for normally preventing withdrawal of said motiontransmitting portion from said end portion, said retaining meanscomprising a cap having a rotatable annular flange permanently securedto said end portion and a collar rigid with said flange and adjacent tosaid end face, said collar having a central opening through which saidtool extends and a recess extending outwardly from said opening, saidrecess being movable into registry with said slot in response torotation of said flange to permit insertion or withdrawal of said motiontransmitting portion from the end portion of said supporting member.

3. In a drilling apparatus, particularly for making holes in concreteand the like, in combination, a rotary supporting member comprising anend portion provided with an inwardly extending axial bore and having aslot extending substantially tangentially from and communicating withsaid bore; an elongated cutting tool having a rotary cutting element atone end and a cylindrically shaped motion transmitting portion at theother end thereof, said motion transmitting portion being slidablyreceived in said bore and having a tangential lateral projectionslidably received in said slot so as to hold the tool against rotationwith respect to said supporting member; and retaining means releasablyengaging said motion transmitting portion for normally preventingwithdrawal of said motion transmitting portion from said end portion.

4. A combination as set forth in claim 3, wherein said retaining meanscomprises a pin received in a transverse bore provided in said endportion and engaging said motion transmitting portion.

5. A combination as set forth in claim 4 wherein said projection has aface which is turned toward said cutting element and wherein said pinengages said face.

6. A combination as set forth in claim 4 wherein said projection has abore which is in registry with said transverse bore and which receives aportion of said pin.

7. A combination as set forth in claim 3 wherein said retaining meanscomprises a threaded member screwed into said end portion and engagingsaid motion transmitting portion.

8. A combination as set forth in claim 7, wherein said threaded memberengages the projection of said motion transmitting portion.

References Cited by the Examiner UNITED STATES PATENTS 348,815 9/1886Bailey 27991 598,173 2/1898 Brendner 279--9 1,149,398 8/1915 Nitteberg2799 1,465,008 8/1923 Stephens 2799 X 1,471,714 10/1923 Veith 27989 XCHARLES F. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner.

1. IN A DRILLING APPARATUS, PARTICULARLY FOR MAKING HOLES IN CONCRETEAND THE LIKE, IN COMBINATION, A ROTARY SUPPORTING MEMBER COMPRISING ANEND PORTION PROVIDED WITH AN INWARDLY EXTENDING AXIAL BORE AND WITH ASLOT EXTENDING SUBSTANTIALLY TANGENTIALLY FROM AND COMMUNICATING WITHSAID BORE; AN ELONGATED CUTTING TOOL OF TUBULAR SHAPE, SAID TOOL HAVINGAN ANNULAR CUTTING ELEMENT AT ONE END AND AN ANNULAR MOTOR TRANSMITTINGPORTION AT THE OTHER END THEREOF, SAID MOTION TRANSMITTING PORTION BEINGSLID-